JPH06160288A - Detector, especially apparatus for surface inspection of cigarette - Google Patents

Abstract

PURPOSE: To inspect a cigarette surface with high precision at low cost and compact device by providing a pair of prism main bodies wherein the light reflected from a quarter part of a cigarette surface is refracted and made into a single reflection beam. CONSTITUTION: On both side surfaces of an observation surface 8 of an optical device 7, a pair of prism main bodies 13 which face each quarter part 6b of a surface 6 of a cigarette 2 in an observation station 5 is provided. The measurement light from light source 19 is reflected, in the direction parallel to the surface 8, on a reflection main body 21 and made incident on the main body 13, and polarized when passing in the main body 13, to form a variable angle against the surface 8, so that each quarter part 6b is irradiated at a best angle. Then the reflection light comes in from a surface 24 to the main body 13, and when comes out of a surface 16, it keeps a direction parallel to the surface 8 and vertical to longitudinal direction axis 9, and through an anamorphic optical device 12, comes in a monitor device 11. At the device 11, the images of two quarter parts 6b are synthesize by reflection light, and then compared to a reference image for detecting an error, and it is judged not acceptable when the error is above a threshold value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detection device, especially for surface inspection of cigarettes.

[0002]

BACKGROUND OF THE INVENTION The quality of the surface of cigarettes emerging from a manufacturing machine is typically inspected by continuous delivery of cigarettes by a type of detection and monitoring device described in U.S. Pat. No. 4,639,592. To be done. It comprises four separate optics, each designed to detect scratches on different types of surfaces on each quadrant of the transverse surface of the cigarette, each of which is It has a light source that illuminates a light beam on each quarter of the lateral surface of the cigarette.

The rays reflected by the surface of each quadrant are focused into a beam which is sent by the respective optical device to a respective monitoring device, which is usually equipped with a telephoto camera. This produces an image that is compared to the sample image inside the monitor and a signal is emitted to repel the cigarette if any major difference between the two images is detected.

Although known detection devices of the type described above are widely used and reasonably reliable from a working point of view, their main drawback is that they are relatively expensive, mainly due to the feature of four monitoring devices. It's expensive.

In addition, known detection devices of the type described above are also relatively awkward, because the surface of each of the cigarette quadrants requires both a light source and an optical device, so that, for example, filter assembly machines. Difficult to put on top of.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a detection device which is designed to overcome the aforementioned drawbacks and which is inexpensive and compact to manufacture, especially as compared to the known devices described above. Is to provide.

Another object of the invention is to provide a detection device designed to work with a very high degree of precision and to provide a built-in detection means with a perfectly formed image.

[0008]

According to the invention, at least one optical device for detecting surface features of each half of the transverse surface of a cigarette; for illuminating said half of said surface A light emitting means for detecting the surface of cigarettes; in particular, the optical device comprises a monitoring device; and a light beam reflected by each part of the half of the surface. Characterized by the fact that it comprises means for refracting and provided for refracting all of the light rays reflected by said half of said surface into a single reflected beam directed to said one monitor device. Things will be provided.

According to a preferred embodiment of the invention, the means for refracting reflected light rays comprises two prism bodies, each facing a quadrant of the cigarette surface.

Non-limiting examples of the present invention will be exemplarily described with reference to the accompanying drawings.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Number 1 in FIG. 1 shows a detection device for surface inspection of cigarettes 2 emerging from a filter assembly machine (not shown).

The device 1 comprises a pair of parallel, counter-rotating rollers 3 (only one of which is partially shown in FIG. 1).
It is equipped with. Each roller 3 has a number of perimeter seats 4 for partially containing the cigarette 2, respectively, and each is rotated about its respective axis (not shown), one for each cigarette. The cigarette 2 is continuously fed to two observation stations 5 (only one shown) which observe each longitudinal half 6a of the lateral surface 6 of the cigarette 2.

For each station 5, the device 1 also comprises an optical device 7 for observing and monitoring the respective half 6a of the surface 6. Each device 7 has a viewing surface 8 containing the longitudinal axis 9 of the cigarette 2 housed in the seat 4 of the station 5, which is on each side of the surface 8 a respective half of the surface 6.
Divide 6a into two quadrants 6b.

The device 7 comprises focusing means having a known spherical optical system 10 acting as a lens; a known monitoring device 11 connected to the spherical optical system 10 in a known manner.
And a device for focusing the light beam on the device 11 together with the spherical optical system, in order to adapt the size of the image of the cigarette 2 to the spherical optical system 10, ie more specifically the photosensitive element. And an anamorphic optical device 12 disposed on the opposite side of the spherical optical system 10 with respect to the device 11 in order to better utilize the detection surface.

The devices 7 are arranged on both sides of the surface 8 and each quadrant 6b of the surface 6 of the cigarette 2 in the station 5.
It also comprises a pair of prism bodies 13 facing each other.

The bodies 13 each have a longitudinal axis (not shown) parallel to the axis 9 and a pentagonal cross section; deflect from the anamorphic optics 12 towards the seat 4; On the side facing 4, it is formed by a respective flat active surface 14 forming a dihedron with its edge in the surface 8 and each forming the same angle B as the surface 8. On the opposite side of the surface 14, each body 13 is parallel to the axis 9 and is inclined with respect to its respective surface 14 and converges in an outward direction,
Formed laterally by two flat surfaces 15 and 16 which are connected to each surface 14 via two flat surfaces 17 and 18 which are also parallel to the axis 9, the surface 18 of which is substantially in plane 8. And is in contact with the surface 18 of the other body 13.

The device 7 has an axis 20 perpendicular to the surface 8 and is oriented so as to impinge on a reflective body 21 arranged between the spherical optical system 10 and the monitor device 11, in a direction parallel to the surface 8. A beam 19a (only half of which is shown in FIG. 2), so that a ray 22 of the beam 19a impinges on the surface 16 of both bodies 13, a source 19 for emitting a beam of light 19a.
Also has.

In practical use, the rays 22 of beam 19a are deflected as they pass through body 13 and are split into two beams 23 (only one of which is shown in FIG. 2),
Each of its rays 24 forms a non-zero variable angle with the surface 8 to provide the best illumination for each quadrant 6b of the surface 6 under observation. Then the incident ray 24 of each beam 23 is
Form reflected light 24a that is reflected by each of the quadrants 6b and that strikes each surface 14 at an angle of incidence within the cone of refraction. Thus, ray 24a passes through each surface 14 and is simply deflected by a predetermined angle of refraction, and ray 24a is directed to form an angle with the normal of surface 15 that is greater than half the angle of the refraction cone. Hit each surface 15. As a result, ray 24a is totally reflected by each surface 15 onto respective surface 14 which reflects ray 24a entirely onto respective surface 16 in a direction substantially parallel to surface 8 such as surface 15. As shown in FIG. 2, surface 16 forms an angle with surface 8 that is very close to 90 °, so that light ray 24a is at a predetermined angle of refraction.
It is simply deflected by 16 and continues in the direction substantially parallel to plane 8 and perpendicular to axis 9. In particular, the ray 24a from both bodies 13 passes through the anamorphic optics 12 and the spherical optical system 10 to reach the monitor 11 by a single beam 19b (only half of which is shown in FIG. 2). ). As it passes through the anamorphic optical device 12, the beam 19b is compressed in a direction parallel to the axis 9 and spread out in a direction perpendicular to the plane 8 so that it exits the device 12 as it exits.
With a cross section more suitable for 11.

The device 11 is arranged so that the beam 19b causes the surface 2
An array of telephoto cameras (not shown) or photosensors which give a composite image of the four quadrants 6b; a known comparison in which the composite image is compared with the image of the specimen to detect any difference between the two And a container (not shown) in a known manner. When a difference equal to or greater than a predetermined threshold is detected, a signal for repelling the cigarette 2 is transmitted by a known method. According to the first variant embodiment, the source 19
Illuminates each quadrant of the surface 6 directly (or via the body 13) by emitting a respective beam 26 (26 '), as indicated by the dash-dotted line, and unlike the source 19. Can be replaced by two light sources 25 (25 ').

[0020]

The body 13, which is relatively simple and inexpensive to manufacture, thus halves the number of monitoring devices required, which not only reduces the production costs significantly, but also on the filter assembly machine. It results in the realization of a relatively compact device which is particularly suitable for use.

[Brief description of drawings]

1 is a partial side view of a preferred embodiment of the device of the present invention.

FIG. 2 is an enlarged detailed view of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Detection device, 2 ... Cigarette, 3 ... Roller (conveyor), 4 ... Seat part, 5 ... Observation station, 6, 14, 15,
16, 17, 18 ... Surface, 7 ... Optical device, 8 ... Observation surface, 9,
20 ... Axis, 10 ... Optical system, 11 ... Monitor device, 12 ... Anamorphic optical device, 13 ... Prism body, 19, 25 ...
Light source, 21 ... Reflective body, 22, 24 ... Rays, 23, 26 ... Beam.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Giancarlo Santin Italy, 40068 San Rustalo di Sabena, Via Bellaria 107 (72) Inventor Stefano Kini Italy, 40068 San Lazzaro, Italy Di Sabena, Via Gramci 11

Claims (7)

[Claims] 1. A lateral surface (6) of a cigarette (2).
At least one optical device (7) for detecting the features of the surface of each half of; and ray emitting means (19; 25, 25 ') for illuminating said half of said surface (6) A detection device, in particular for detecting the surface of cigarettes (2); said optical device (7) being one monitor device (11); reflected by each part of said half of said surface (6) For refracting the rays of light to be reflected and for refracting all of the rays of light reflected by the half of the surface (6) into a single reflected beam directed at the one monitoring device (11). A detection device characterized by the fact that it comprises means (13). 2. The reflected light refracting means of claim 1, characterized in that it comprises two prism bodies (13) each facing a quadrant of the surface (6) of the cigarette (2). apparatus. 3. A longitudinal surface (8) in which the two prism bodies (13) cross the axis of the cigarette (2) in use and divide the half of the surface (6) into two quadrants. 3.) Device according to claim 2, characterized in that they are substantially tangential to each other along and extend away from the opposite sides of said face (8). 4. The prism body (13) is attached to a side surface facing the cigarette (2) when in use, and the prism body (13) is provided with the surface (8).
4. Device according to claim 3, characterized by being formed by respective flat active surfaces (14) forming a dihedron with its edge inside. 5. Device according to claim 4, characterized in that the active surface (14) is inclined by the same angle (B) with respect to the surface (8). 6. Means (1) for the optical device (7) to focus the reflected beam onto the monitor device (11).
Device according to any one of claims 1 to 5, characterized in that it also comprises 2). 7. The concentrating means is characterized in that it comprises anamorphic optical means (12) and image focusing means (10) arranged in series along the reflected beam. The described device.